add--interactive: drop diff.indentHeuristic handling

Now that diff.indentHeuristic is handled automatically by the plumbing
commands, there's no need to propagate it manually.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Marc Branchaud <marcnarc@xiplink.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-add--interactive.perl

@@ -46,7 +46,6 @@ my ($diff_new_color) =
 my $normal_color = $repo->get_color("", "reset");
 
 my $diff_algorithm = $repo->config('diff.algorithm');
-my $diff_indent_heuristic = $repo->config_bool('diff.indentheuristic');
 my $diff_filter = $repo->config('interactive.difffilter');
 
 my $use_readkey = 0;
@@ -730,9 +729,6 @@ sub parse_diff {
 	if (defined $diff_algorithm) {
 		splice @diff_cmd, 1, 0, "--diff-algorithm=${diff_algorithm}";
 	}
-	if ($diff_indent_heuristic) {
-		splice @diff_cmd, 1, 0, "--indent-heuristic";
-	}
 	if (defined $patch_mode_revision) {
 		push @diff_cmd, get_diff_reference($patch_mode_revision);
 	}